Compositions comprising a copolymer of a solid grade oligomer and a hydrophobic monomer and/or a gas-phase monomer and methods of making the same

ABSTRACT

The present disclosure relates to compositions comprising a copolymer derived from polymerizing a hydrophobic monomer and/or a gas-phase monomer in the presence of a solid grade oligomer. In some embodiments, the hydrophobic monomer includes styrene and butadiene. In some embodiments, the copolymer is derived from polymerizing a gas-phase monomer. The present disclosure also relates to methods of making the disclosed compositions. The compositions disclosed herein can be used in a variety of applications including, but not limited to, asphalt compositions, paints, coatings, paper binding and coating compositions, foams, or adhesives.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.61/790,608 filed Mar. 15, 2013, the disclosure of which is herebyincorporated by reference in its entirety.

FIELD OF THE DISCLOSURE

The present disclosure relates to compositions comprising a copolymerderived from polymerizing a hydrophobic monomer and/or a gas-phasemonomer in the presence of a solid grade oligomer. The presentdisclosure also relates to methods of making the disclosed compositions.

BACKGROUND

Certain polymerization processes using hydrophobic monomers and/orgas-phase monomers occur at high polymerization pressures that requirespecial equipment to withstand the high pressures. For instance,conventional styrene-butadiene polymerizations are conducted using highpolymerization pressures, particularly when higher amounts of butadienemonomer are used. In addition, the polymerization of gas-phase monomerssuch as ethylene often requires high polymerization pressures. As analternative to higher polymerization pressures, long polymerizationreaction times are used resulting in less throughput and lower levels ofproduction. The polymerization temperature can be increased to reducethe pressure or reaction time for polymerization, but adjustments totemperature are limited. Therefore, finding a way to conductpolymerization processes such as styrene-butadiene and ethylenepolymerization processes at lower pressure without increasing reactiontime or temperature is desirable.

SUMMARY OF THE DISCLOSURE

Disclosed herein are compositions comprising a copolymer derived frompolymerizing a hydrophobic and/or a gas-phase monomer in the presence ofa solid grade oligomer. In some embodiments, the copolymer is furtherderived from a hydrophilic monomer (e.g., a carboxylic acid monomer). Insome embodiments, the hydrophobic monomer includes styrene, butadiene, acarboxylic acid-based hydrophobic monomer, or a mixture thereof. In someembodiments, the copolymer is derived from a hydrophobic monomer. Thehydrophobic monomer can include styrene and a (meth)acrylic acid-basedmonomer (e.g., a (meth)acrylic acid-based hydrophobic monomer). Thehydrophobic monomer can consist of butadiene. The hydrophobic monomercan include styrene and butadiene. In some embodiments, the copolymer isderived from 4%-80% by weight styrene, 4%-80% by weight butadiene, and8%-25% by weight solid grade oligomer. In some embodiments, thecopolymer is derived from 25%-59% by weight styrene, 25%-59% by weightbutadiene, and 8%-25% by weight solid grade oligomer. In someembodiments, the copolymer is derived from a gas-phase monomer.Exemplary gas-phase monomers include, but are not limited to, ethylene,propylene, isobutylene, vinyl chloride, vinylidene chloride, or mixturesthereof. In some embodiments, the copolymer is further derived fromvinyl acetate. For instance, the copolymer can be derived from greaterthan 0% ethylene and 81% or less vinyl acetate. In some embodiments, thecopolymer is derived from 16%-41% by weight ethylene, 41%-67% by weightvinyl acetate, and 8%-25% by weight solid grade oligomer.

In some embodiments, the solid grade oligomer is derived from a vinylaromatic monomer (e.g., styrene, α-methyl styrene, or a combinationthereof). The solid grade oligomer can be further derived from acarboxylic acid monomer (e.g., acrylic acid), or a salt or esterthereof. In some embodiments, the solid grade oligomer is an amine saltof a modified acrylic copolymer, an ammonium salt of a modified acryliccopolymer, or a combination thereof. In some embodiments, the copolymeris crosslinked (e.g., via ionic crosslinking). The compositionsdisclosed herein can be used, for instance, in an asphalt composition, apaint, a coating, a paper coating or binding composition, a carpetcomposition, an adhesive, or a foam.

The compositions disclosed herein can be aqueous dispersions comprisingthe copolymers disclosed herein. In some embodiments, the aqueousdispersions have a solids content of at least 50% and a viscosity offrom 40 cP to 5,000 cP at 20° C. In some embodiments, the copolymer isprovided as a powder.

Also disclosed herein are methods of preparing a copolymer, comprisingpolymerizing a hydrophobic monomer and a solid grade oligomer and/or agas-phase monomer in an aqueous medium. The polymerizing step can be anemulsion polymerization step. Also disclosed herein are methods ofreducing the reaction time in producing a copolymer, comprisingpolymerizing a hydrophobic monomer and/or a gas-phase monomer and asolid grade oligomer using emulsion polymerization, wherein the reactiontime is reduced without increasing the temperature or pressure of thepolymerization step compared to the same polymerization step without thesolid grade oligomer. Also disclosed herein are methods of reducing thereaction pressure in producing a copolymer, comprising polymerizing ahydrophobic monomer and/or a gas-phase monomer and a solid gradeoligomer using emulsion polymerization, wherein the reaction pressure isreduced without increasing the temperature or reaction time of thepolymerization step compared to the same polymerization step without thesolid grade oligomer. Also disclosed herein are methods of reducing thereaction temperature in producing a copolymer, comprising polymerizing ahydrophobic monomer and/or a gas-phase monomer and a solid gradeoligomer using emulsion polymerization, wherein the reaction temperatureis reduced without increasing the pressure or reaction time of thepolymerization step compared to the same polymerization step without thesolid grade oligomer.

The details of one or more embodiments are set forth in the descriptionbelow. Other features, objects, and advantages will be apparent from thedescription and from the claims.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 illustrates the temperature and pressure over run time for thepolymerization of a copolymer comprising 50 parts by weight styrene and50 parts by weight butadiene.

FIG. 2 illustrates the temperature and pressure over run time for thepolymerization of a copolymer comprising 50 parts by weight styrene, 50parts by weight butadiene, and 20 parts by weight solid grade oligomer(SGO).

FIG. 3 illustrates the temperature and pressure over run time for thepolymerization of a copolymer comprising 40 parts by weight styrene, 60parts by weight butadiene, and 20 parts by weight solid grade oligomer(SGO).

FIG. 4 illustrates the temperature and pressure over run time for thepolymerization of a copolymer comprising 30 parts by weight styrene, 70parts by weight butadiene, and 20 parts by weight solid grade oligomer(SGO).

FIG. 5 illustrates the temperature and pressure over run time for thepolymerization of a copolymer comprising 50 parts by weight styrene, 50parts by weight butadiene, and 20 parts by weight of an alternate solidgrade oligomer (SGO).

FIG. 6 illustrates the temperature and pressure over run time for thepolymerization of a copolymer comprising 50 parts by weight styrene, 50parts by weight butadiene, and 20 parts by weight of an alternate solidgrade oligomer (SGO).

FIG. 7 illustrates a comparison of temperature to complex modulus forcopolymers comprising 50 parts by weight styrene, 50 parts by weightbutadiene, and various amounts of solid grade oligomer (SGO).

FIG. 8 illustrates a comparison of temperature to complex modulus forcopolymers comprising 20 parts of solid grade oligomer (SGO) and variousamounts of styrene and butadiene.

FIG. 9 illustrates the temperature and pressure over run time for thepolymerization of a copolymer comprising 50 parts by weight styrene, 50parts by weight butadiene, and 20 parts by weight solid grade oligomer(SGO) and depicting a decrease in polymerization time.

FIG. 10 illustrates the temperature and pressure over run time for thepolymerization of a copolymer comprising 50 parts by weight styrene, 50parts by weight butadiene, and 20 parts by weight solid grade oligomer(SGO) and depicting a decrease in polymerization time.

FIG. 11 depicts the impact of certain styrene butadiene copolymers,including copolymers as described in this disclosure, on asphaltviscosity.

DETAILED DESCRIPTION

Disclosed herein are compositions comprising a copolymer derived frompolymerizing a hydrophobic monomer and/or gas-phase monomer in thepresence of a solid grade oligomer, and methods of making and using thesame. As used herein, a “hydrophobic monomer” comprises a monomer havinga water solubility of less than 1 g/100 g water at 20° C. As usedherein, a “gas-phase monomer” is a monomer that is a gas at 20° C. andatmospheric pressure.

The compositions disclosed herein comprise a copolymer derived from ahydrophobic monomer and/or gas-phase monomer (i.e., a hydrophobicmonomer, a gas-phase monomer, or a mixture thereof). In someembodiments, the copolymer is derived from a hydrophobic monomer. Thehydrophobic monomer can include any hydrophobic monomer known in theart. In some embodiments, the hydrophobic monomer includes styrene,butadiene, a carboxylic acid-based hydrophobic monomer, or a mixturethereof.

Exemplary carboxylic acid-based hydrophobic monomers include, but arenot limited to, hydrophobic esters of α,β-monoethylenically unsaturatedmono- and dicarboxylic acids having 3 to 6 carbon atoms with alkanolshaving 1 to 12 carbon atoms (e.g., esters of acrylic acid, methacrylicacid, maleic acid, fumaric acid, or itaconic acid, with alkanols such asn-butyl, isobutyl and 2-ethylhexyl acrylates and methacrylates, andn-butyl maleate). In some embodiments, the carboxylic acid-basedhydrophobic monomer is a (meth)acrylic acid-based hydrophobic monomer.As used herein, the term “(meth)acryl . . . ” refers to “acryl . . . ”and “methacryl . . . .” In some embodiments, the (meth)acrylicacid-based hydrophobic monomer includes butyl acrylate, 2-ethylhexylacrylate, or mixtures thereof.

In some embodiments, the copolymer is derived from a gas-phase monomer.Exemplary gas-phase monomers include, but are not limited to, ethylene,vinyl chloride, vinylidene chloride, propylene, isobutylene, or amixture thereof.

The solubility of the hydrophobic monomers in water, measured at 20° C.,can be 1 g/100 g water or less, 0.6 g/100 g water or less, 0.2 g/100 gwater or less, 0.1 g/100 g water or less, 0.05 g/100 g water or less,0.03 g/100 g water or less, or 0.01 g/100 g water or less. Suitablehydrophobic monomers include as noted herein butyl acrylate (0.16 g/100g water); butadiene (0.08 g/100 g water); styrene (0.03 g/100 g water);2-ethylhexyl acrylate (0.01 g/100 g water); vinyl neo-pentanoate (0.08g/100 g water); vinyl 2-ethylhexanoate (less than 0.01 g/100 g water);vinyl neo-nonanoate (less than 0.001 g/100 g water); vinyl neo-decanoate(less than 0.001 g/100 g water); vinyl neo-undecanoate (less than 0.001g/100 g water); and vinyl neo-dodecanoate (less than 0.001 g/100 gwater). Solubilities can be provided, e.g., from D. R. Bassett,“Hydrophobic Coatings for Emulsion Polymers,” Journal of CoatingsTechnology, January 2001, or High Polymers Vol. IX: EmulsionPolymerization, F. A. Bovey, I. M. Kolthoff, A. I. Medalia and E. J.Meehan, p. 156, 1954.

In some embodiments, the copolymer is derived from 1% or greater, 3% orgreater, 5% or greater, 7.5% or greater, 10% or greater, 15% or greater,20% or greater, 25% or greater, 30% or greater, 35% or greater, 40% orgreater, 45% or greater, 50% or greater, 55% or greater, 60% or greater,65% or greater, 70% or greater, 75% or greater, 80% or greater, 85% orgreater, or 90% or greater by weight of the hydrophobic monomer and/orgas phase monomer. In some embodiments, the copolymer is derived from92% or less, 90% or less, 85% or less, 80% or less, 75% or less, 70% orless, 65% or less, 60% or less, 55% or less, 50% or less, 45% or less,40% or less, 35% or less, 30% or less, 25% or less, 20% or less, 15% orless, 10% or less, 7.5% or less, 5% or less, or 3% or less by weight ofthe hydrophobic monomer and/or gas phase monomer.

The copolymers disclosed herein can be further derived from ahydrophilic monomer. The hydrophilic monomer can include a carboxylicacid monomer, for instance. Exemplary hydrophilic monomers include, butare not limited to, α,β-monoethylenically unsaturated mono- anddicarboxylic acids, citraconic acid, styrene carboxylic acid,(meth)acrylic acid, itaconic acid, fumaric acid, crotonic acid,dimethacrylic acid, ethylacrylic acid, allylacetic acid, vinylaceticacid, maleic acid, mesaconic acid, methylenemalonic acid, and citraconicacid. Exemplary hydrophilic monomers include carboxylic acid-basedmonomers such as hydrophilic esters of α,β-monoethylenically unsaturatedmono- and dicarboxylic acids having 3 to 6 carbon atoms with alkanolshaving 1 to 12 carbon atoms (e.g., esters of acrylic acid, methacrylicacid, maleic acid, fumaric acid, or itaconic acid, with alkanols such asn-ethyl acrylate, methyl acrylate, methyl methacrylate, and dimethylmaleate). Exemplary hydrophilic monomers can also include vinyl acetate,(meth)acrylonitrile, or (meth)acrylamide.

In some embodiments, the copolymer is derived from 1% or greater, 2% orgreater, 3% or greater, 4% or greater, 5% or greater, 7.5% or greater,10% or greater, 15% or greater, 20% or greater, 25% or greater, 30% orgreater, 35% or greater, 40% or greater, 45% or greater, 50% or greater,55% or greater, 60% or greater, 65% or greater, 70% or greater, 75% orgreater, 80% or greater, or 85% or greater by weight of the hydrophilicmonomer. In some embodiments, the copolymer is derived from 90% or less,85% or less, 80% or less, 75% or less, 70% or less, 65% or less, 60% orless, 55% or less, 50% or less, 45% or less, 40% or less, 35% or less,30% or less, 25% or less, 20% or less, 15% or less, 10% or less, 7.5% orless, 5% or less, 4% or less, 3% or less, 2% or less, or 1% or less byweight of the hydrophilic monomer.

The copolymers disclosed herein can be derived from additionalhydrophobic or hydrophilic monomers, and particularly in small amounts(e.g., 10% by weight or less, 7.5% by weight or less, 5% by weight orless, 4% by weight or less, 3% by weight or less, 2% by weight or less,1.5% by weight or less, 1% by weight or less, or 0.5% by weight orless). Exemplary additional monomers include other vinylaromaticcompounds (e.g., α-methylstyrene, o-chlorostyrene, and vinyltoluenes);isoprene; anhydrides of α,β-monoethylenically unsaturated monocarboxylicand dicarboxylic acids (e.g., maleic anhydride, itaconic anhydride, andmethylmalonic anhydride); other alkyl-substituted acrylamides (e.g.,N-tert-butylacrylamide and N-methyl(meth)acrylamide); vinyl andvinylidene halides (e.g., vinyl chloride and vinylidene chloride); vinylesters of C1-C18 monocarboxylic or dicarboxylic acids (e.g., vinylacetate, vinyl propionate, vinyl n-butyrate, vinyl laurate and vinylstearate); C1-C4 hydroxyalkyl esters of C3-C6 monocarboxylic ordicarboxylic acids, especially of acrylic acid, methacrylic acid ormaleic acid, or their derivatives alkoxylated with from 2 to 50 moles ofethylene oxide, propylene oxide, butylene oxide or mixtures thereof, oresters of these acids with C1-C18 alcohols alkoxylated with from 2 to 50mol of ethylene oxide, propylene oxide, butylene oxide or mixturesthereof (e.g., hydroxyethyl(meth)acrylate, hydroxypropyl(meth)acrylate,and methylpolyglycol acrylate); and monomers containing glycidyl groups(e.g., glycidyl methacrylate), linear 1-olefins, branched-chain1-olefins or cyclic olefins (e.g., ethene, propene, butene, isobutene,pentene, cyclopentene, hexene, and cyclohexene); vinyl and allyl alkylethers having 1 to 40 carbon atoms in the alkyl radical, wherein thealkyl radical can possibly carry further substituents such as a hydroxylgroup, an amino or dialkylamino group, or one or more alkoxylated groups(e.g., methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether,isobutyl vinyl ether, 2-ethylhexyl vinyl ether, vinyl cyclohexyl ether,vinyl 4-hydroxybutyl ether, decyl vinyl ether, dodecyl vinyl ether,octadecyl vinyl ether, 2-(diethylamino)ethyl vinyl ether,2-(di-n-butylamino)ethyl vinyl ether, methyldiglycol vinyl ether, andthe corresponding allyl ethers); sulfo-functional monomers (e.g.,allylsulfonic acid, methallylsulfonic acid, styrenesulfonate,vinylsulfonic acid, allyloxybenzenesulfonic acid,2-acrylamido-2-methylpropanesulfonic acid, and their correspondingalkali metal or ammonium salts, sulfopropyl acrylate and sulfopropylmethacrylate); vinylphosphonic acid, dimethyl vinylphosphonate, andother phosphorus monomers (e.g., phosphoethyl (meth)acrylate);alkylamino alkyl(meth)acrylates or alkylaminoalkyl(meth)acrylamides orquaternization products thereof (e.g.,2-(N,N-dimethylamino)ethyl(meth)acrylate,3-(N,N-dimethylamino)propyl(meth)acrylate,2-(N,N,N-trimethylammonium)ethyl(meth)acrylate chloride,2-dimethylaminoethyl(meth)acrylamide,3-dimethylaminopropyl(meth)acrylamide, and3-trimethylammoniumpropyl(meth)acrylamide chloride); allyl esters ofC1-C30 monocarboxylic acids; N-Vinyl compounds (e.g., N-vinylformamide,N-vinyl-N-methylformamide, N-vinylpyrrolidone, N-vinylimidazole,1-vinyl-2-methylimidazole, 1-vinyl-2-methylimidazoline,N-vinylcaprolactam, vinylcarbazole, 2-vinylpyridine, and4-vinylpyridine); monomers containing 1,3-diketo groups (e.g.,acetoacetoxyethyl(meth)acrylate or diacetonacrylamide; monomerscontaining urea groups (e.g., ureidoethyl(meth)acrylate,acrylamidoglycolic acid, and methacrylamidoglycolate methyl ether);monoalkyl itaconates; monoalkyl maleates; hydrophobic branched estermonomers; monomers containing silyl groups (e.g., trimethoxysilylpropylmethacrylate), vinyl esters of branched mono-carboxylic acids having atotal of 8 to 12 carbon atoms in the acid residue moiety and 10 to 14total carbon atoms such as, vinyl 2-ethylhexanoate, vinyl neo-nonanote,vinyl neo-decanoate, vinyl neo-undecanoate, vinyl neo-dodecanoate andmixtures thereof, and copolymerizable surfactant monomers (e.g., thosesold under the trademark ADEKA REASOAP).

The copolymers disclosed herein can also be derived from a crosslinkingagent. Exemplary crosslinking agents include, but are not limited to,N-alkylolamides of α,β-monoethylenically unsaturated carboxylic acidshaving 3 to 10 carbon atoms and esters thereof with alcohols having 1 to4 carbon atoms (e.g., N-methylolacrylamide andN-methylolmethacrylamide); glyoxal based crosslinkers; monomerscontaining two vinyl radicals; monomers containing two vinylideneradicals; and monomers containing two alkenyl radicals. Exemplarycrosslinking agents can include, for instance, diesters of dihydricalcohols with α,β-monoethylenically unsaturated monocarboxylic acids, ofwhich in turn acrylic acid and methacrylic acid can be employed.Examples of such monomers containing two non-conjugated ethylenicallyunsaturated double bonds can include alkylene glycol diacrylates anddimethacrylates, such as ethylene glycol diacrylate, 1,3-butylene glycoldiacrylate, 1,4-butylene glycol diacrylate and propylene glycoldiacrylate, divinylbenzene, vinyl methacrylate, vinyl acrylate, allylmethacrylate, allyl acrylate, diallyl maleate, diallyl fumarate andmethylenebisacrylamide. In some embodiments, the crosslinking agents caninclude alkylene glycol diacrylates and dimethacrylates, and/ordivinylbenzene.

In addition to being derived from a hydrophobic monomer and/or gas-phasemonomer, the copolymers disclosed herein are derived from a solid gradeoligomer. In other words, the solid grade oligomer reacts during thepolymerization and becomes part of the copolymer. In some embodiments,the copolymer is derived from 8%-25% by weight solid grade oligomer(e.g., from 10%-25%, from 13%-24.5%, from 16%-24%, or from 17%-23%). Insome embodiments, the solid grade oligomer includes an ammonium salt ofa modified acrylic copolymer, an amine salt of a modified acryliccopolymer, or a combination thereof. In some embodiments, the solidgrade oligomer is derived from styrene and α-methyl styrene and includescarboxyl groups. In some embodiments, the solid grade oligomer derivedfrom styrene, α-methyl styrene, and a monomer that provides carboxylgroups (e.g., acrylic acid). In some embodiments, the solid gradeoligomer comprises about 33% styrene, about 33% α-methyl styrene, andabout 33% acrylic acid. Exemplary commercially available solid gradeoligomers include, but are not limited to, SGO Resin B-98 (BASF Corp.),SGO Resin E-08 (BASF Corp.), SGO Resin E-26 (BASF Corp.), SGO Resin B-38(BASF Corp.), SGO Resin B-39 (BASF Corp.), and SGO Resin B-57 (BASFCorp.).

Without wishing to be bound by theory, it is believed that the solidgrade oligomer can impact the polymerization of the hydrophobic monomerand/or gas-phase monomer by two mechanisms: (1) by increasing thesolubility of the hydrophobic monomer and/or gas-phase monomer, thusfacilitating transport of the hydrophobic monomer and/or gas-phasemonomer through the aqueous phase to the particles; and (2) by creatingnew particles (i.e., increasing particle nucleation in excess of what isachieved by micellar nucleation and/or a seed latex). Both of thesefactors would explain the observed increase in reaction rate of thepolymerization process. Accordingly, the solid grade oligomer can bechosen from any solid grade oligomer that increases the solubility ofthe hydrophobic monomer and/or gas-phase monomer, creates new particlesduring polymerization, or a combination thereof. The solid gradeoligomer can be chosen from any solid grade oligomer that allows fordecreased polymerization pressure when polymerizing hydrophobic monomersand/or gas-phase monomers without increasing reaction time ortemperature.

In some embodiments, the copolymer is derived from only one hydrophobicmonomer and/or gas-phase monomer (i.e., consists of one hydrophobicmonomer or consists of one gas-phase monomer). For example, thecopolymer can be formed by polymerizing the solid grade oligomer with ahydrophobic monomer and/or gas-phase monomer selected from styrene,butadiene, ethylene, propylene, isobutylene, vinyl chloride, orvinylidene chloride. In some embodiments, the copolymer is derived fromtwo or more hydrophobic monomers, gas-phase monomers, or mixturesthereof. As noted above, the copolymer can optionally also be derivedfrom one or more hydrophilic monomers. The copolymer can be a random,alternating, or block copolymer depending on the SGO, the hydrophobicmonomer(s) and/or the gas-phase monomer(s), and optionally thehydrophilic monomer(s) used to produce the copolymer.

In some embodiments, the hydrophobic monomer includes styrene andbutadiene. In some embodiments, the copolymer is derived from 4%-80% byweight styrene (e.g., from 10%-70%, from 15%-65%, from 20%-62%, from25%-59%, from 28%-48%, or from 32%-42%), from 4%-80% by weight butadiene(e.g., from 10%-70%, from 15%-65%, from 25%-62%, from 25%-62%, from42%-59%, or from 44%-55%), and from 8%-25% by weight solid gradeoligomer (e.g., from 12%-25%, from 16%-24%, or from 17%-23%). In someembodiments, the copolymer can be derived from one or more monomers inaddition to styrene and butadiene such as (meth)acrylonitrile,(meth)acrylamide and/or a carboxylic acid monomer (e.g., (meth)acrylicacid).

In some embodiments, the hydrophobic monomer includes styrene and a(meth)acrylic acid-based monomer. For example, the (meth)acrylicacid-based monomer can be a (meth)acrylic acid-based hydrophobic monomersuch as butyl acrylate or 2-ethylhexyl acrylate. In some embodiments,the (meth)acrylic acid-based monomer can be a (meth)acrylic acid-basedhydrophilic monomer such as ethyl acrylate, methyl acrylate, or methylmethacrylate. In some embodiments, the copolymer is derived from 4%-80%by weight styrene (e.g., from 10%-75%, from 15%-70%, from 20%-65%, from25%-60%, from 30%-55%, from 35%-50%, or from 37%-47%), from 4%-80% byweight (meth)acrylic acid-based hydrophobic monomer (e.g., from 10%-75%,from 15%-70%, from 20%-65%, from 25%-60%, from 30%-55%, from 35%-50%, orfrom 37%-47%), and from 8%-25% by weight solid grade oligomer (e.g.,from 12%-25%, from 16%-24%, or from 17%-23%). In some embodiments, thecopolymer can be derived from one or more monomers in addition tostyrene and a (meth)acrylic acid-based hydrophobic monomer such as(meth)acrylamide, a carboxylic acid monomer (e.g., (meth)acrylic acid),a phosphate-based monomer (e.g., PEM), an acetoacetoxy monomer (e.g.,AAEM), or another functional monomer.

In some embodiments, the copolymer is derived from a gas-phase monomer.Exemplary gas-phase monomers include, but are not limited to, ethylene,vinyl chloride, vinylidene chloride, propylene, isobutylene, or mixturesthereof. In some embodiments, the gas-phase monomer is ethylene and thecopolymer is further derived from vinyl acetate. In some embodiments,the copolymer is derived from greater than 0% by weight ethylene (e.g.,greater than 5%, greater than 10%, greater than 15%, greater than 20%,greater than 25%, greater than 30%, greater than 35%, greater than 40%).In some embodiments, the copolymer is derived from 16%-41% by weightethylene (e.g., from 20%-35%, or from 25%-30%). In some embodiments, thecopolymer is derived from 81% or less by weight vinyl acetate (e.g., 80%or less, 75% or less, 70% or less, 65% or less, 60% or less, 55% orless, 50% or less, 45% or less, or 40% or less). In some embodiments,the copolymer is derived from 41%-67% by weight vinyl acetate (e.g.,from 45%-65%, or from 50%-60%). In some embodiments, the copolymer isderived from 16%-41% by weight ethylene (e.g., from 20%-35%, or from25%-30%), from 41%-67% by weight vinyl acetate (e.g., from 45%-65%, orfrom 50%-60%), and from 8%-25% by weight solid grade oligomer (e.g.,from 12%-25%, from 16%-24%, or from 17%-23%). In some embodiments, thecopolymer is derived from ethylene and one or more of styrene,butadiene, and a carboxylic acid-based hydrophobic monomer.

The glass transition temperature (T_(g)) of the copolymers present inthe composition is from −80° C. to 100° C. (e.g., from −70° C. to 90°C., from −60° C. to 80° C., from −50° C. to 70° C., from −40° C. to 60°C., from −30° C. to 50° C., from −20° C. to 40° C., or from −10° C. to30° C.). The T_(g) can be measured using differential scanningcalorimetry (DSC).

The compositions disclosed herein can be prepared by any polymerizationmethod known in the art. In some embodiments, the compositions disclosedherein are prepared by a dispersion, a mini-emulsion, or an emulsionpolymerization. The compositions disclosed herein can be prepared, forinstance, by polymerizing the hydrophobic monomer and/or gas-phasemonomer in the presence of a solid grade oligomer using free-radicalaqueous emulsion polymerization. The emulsion polymerization can be anaqueous emulsion comprising water, a hydrophobic monomer and/orgas-phase monomer, a solid grade oligomer, a cationic emulsifier, anaromatic recycling agent, or combinations thereof. In some embodiments,the polymerization medium is an aqueous medium. Solvents other thanwater can be used in the emulsion. The emulsion polymerization can becarried out either as a batch, semi-batch, or continuous process. Insome embodiments, a portion of the monomers can be heated to thepolymerization temperature and partially polymerized, and the remainderof the polymerization batch can be subsequently fed to thepolymerization zone continuously, in steps or with superposition of aconcentration gradient. The process can use a single reactor or a seriesof reactors as would be readily understood by those skilled in the art.For example, a review of heterophase polymerization techniques isprovided in M. Antonelli and K. Tauer, Macromol. Chem. Phys. 2003, vol.204, p 207-19.

A copolymer dispersion can be prepared by first charging a reactor withwater, a hydrophobic monomer and/or gas-phase monomer, a solid gradeoligomer, and optionally at least one nonionic surfactant. A seed latex,though optional, can be included in the reactor to help initiatepolymerization and helps produce a polymer having a consistent particlesize. Any seed latex appropriate for the specific monomer reaction canbe used such as a polystyrene seed. The initial charge can also includea chelating or complexing agent such as ethylenediamine tetraacetic acid(EDTA). Other compounds such as buffers can be added to the reactor toprovide the desired pH for the emulsion polymerization reaction. Forexample, bases or basic salts such as KOH or tetrasodium pyrophosphatecan be used to increase the pH whereas acids or acidic salts can be usedto decrease the pH. The initial charge can then be heated to atemperature at or near the reaction temperature, for example, to between50° C. and 100° C. (e.g., between 55° C. and 95° C., between 58° C. and90° C., between 61° C. and 85° C., between 65° C. and 80° C., or between68° C. and 75° C.).

After the initial charge, the monomers that are to be used in thepolymerization can be continuously fed to the reactor in one or moremonomer feed streams. The monomers can be supplied as a pre-emulsion inan aqueous medium, particularly if acrylate monomers are used in thepolymerization. An initiator feed stream can be also continuously addedto the reactor at the time the monomer feed stream is added although itmay also be desirable to include at least a portion of the initiatorsolution to the reactor before adding a monomer pre-emulsion if one isused in the process. The monomer and initiator feed streams aretypically continuously added to the reactor over a predetermined periodof time (e.g., 1.5-5 hours) to cause polymerization of the monomers andto thereby produce the polymer dispersion. A nonionic surfactant and anyother surfactants can be added at this time as part of either themonomer stream or the initiator feed stream although they can beprovided in a separate feed stream. Furthermore, one or more buffers canbe included in either the monomer or initiator feed streams or providedin a separate feed stream to modify or maintain the pH of the reactor.

As mentioned above, the monomer feed stream can include one or moremonomers (e.g., the hydrophobic monomer and/or the gas-phase monomer)and the solid grade oligomer. The monomers can be fed in one or morefeed streams with each stream including one or more of the monomersbeing used in the polymerization process. For example, styrene andbutadiene (when used) can be provided in separate monomer feed streamsor can be added as a pre-emulsion. It can also be advantageous to delaythe feed of certain monomers to provide certain polymer properties or toprovide a layered or multiphase structure (e.g., a core/shellstructure).

The molecular weight of the copolymers can be adjusted by adding a smallamount of molecular weight regulators, for example, 0.01 to 4% byweight, based on the monomers being polymerized. Particular regulatorswhich can be used include organic thio compounds (e.g.,tert-dodecylmercaptan), allyl alcohols and aldehydes.

The initiator feed stream can include at least one initiator orinitiator system that is used to cause the polymerization of themonomers in the monomer feed stream. The initiator stream can alsoinclude water and other desired components appropriate for the monomerreaction to be initiated. The initiator can be any initiator known inthe art for use in emulsion polymerization such as azo initiators;ammonium, potassium or sodium persulfate; or a redox system thattypically includes an oxidant and a reducing agent. Commonly used redoxinitiation systems are described, e.g., by A. S. Sarac in Progress inPolymer Science 24, 1149-1204 (1999). Exemplary initiators include azoinitiators and aqueous solutions of sodium persulfate. The initiatorstream can optionally include one or more buffers or pH regulators.

In addition to the monomers and initiator, an anionic or nonionicsurfactant (i.e., emulsifier) such as those described herein can be fedto the reactor. The surfactant can be provided in the initial charge ofthe reactor, provided in the monomer feed stream, provided in an aqueousfeed stream, provided in a pre-emulsion, provided in the initiatorstream, or a combination thereof. The surfactant can also be provided asa separate continuous stream to the reactor. The surfactant can beprovided in an amount of 1%-5% by weight, based on the total weight ofmonomer and surfactant. In some embodiments, the surfactant is providedin an amount less than 2% by weight.

Once polymerization is completed, the polymer dispersion can bechemically stripped thereby decreasing its residual monomer content.This stripping process can include a chemical stripping step and/or aphysical stripping step. In some embodiments, the polymer dispersion ischemically stripped by continuously adding an oxidant such as a peroxide(e.g., t-butylhydroperoxide) and a reducing agent (e.g., sodium acetonebisulfite), or another redox pair to the reactor at an elevatedtemperature and for a predetermined period of time (e.g., 0.5 hours).Suitable redox pairs are described by A. S. Sarac in Progress in PolymerScience 24, 1149-1204 (1999). An optional defoamer can also be added ifneeded before or during the stripping step. In a physical strippingstep, a water or steam flush can be used to further eliminate thenon-polymerized monomers in the dispersion. Once the stripping step iscompleted, the pH of the polymer dispersion can be adjusted and abiocide or other additives can be added. Cationic, anionic, and/oramphoteric surfactants or polyelectrolytes may optionally be added afterthe stripping step or at a later time if desired in the end product toprovide a cationic or anionic polymer dispersion.

Once the polymerization reaction is complete, and the stripping step iscompleted, the temperature of the reactor can be reduced.

The methods disclosed herein can also include a crosslinking step. Insome embodiments, the crosslinking agent is ionic. In some embodiments,the ionic crosslinking agent has a valency of at least 2, at least 3, orat least 4 (e.g., 2, 3, 4, 5 or 6). In some embodiments, the ioniccrosslinking agent includes zirconium. In some embodiments, the ioniccrosslinking agent includes ammonium zirconium carbonate. The ioniccrosslinking agent can be used in an amount of from 0.01% to 5% byweight, based on the weight of the copolymer. Commercially availablecrosslinking agents include, but are not limited to, BACOTE-20, PROTECZZA, ZINPLEX-15, and SILANE Z-6040.

In some embodiments, the polymer particles of the resultant polymerdispersion have an volume-average particle size from 20 nm to 500 nm(e.g., from 40 nm to 480 nm, from 60 nm to 460 nm, from 80 nm to 440 nm,from 100 nm to 420 nm, from 120 nm to 400 nm, from 140 nm to 380 nm,from 160 nm to 360 nm, from 180 nm to 340 nm, from 200 nm to 320 nm, orfrom 220 nm to 300 nm, or from 240 nm to 280 nm). In some embodiments,the polymer particles of the resultant polymer dispersion have a numberaverage particle size of 20 nm to 300 nm (e.g., from 30 nm to 290 nm,from 40 nm to 280 nm, from 50 nm to 270 nm, from 60 nm to 260 nm, from70 nm to 250 nm, from 80 nm to 240 nm, from 90 nm to 230 nm, from 100 nmto 220 nm, from 110 nm to 210 nm, from 120 nm to 200 nm, from 130 nm to190 nm, or from 140 nm to 180 nm). The particle size measurements aremade using dynamic light scattering measurements using the Nicomp Model380 available from Particle Sizing Systems, Santa Barbara, Calif.

The copolymer can be produced as a dispersion that includes, as adisperse phase, particles of the copolymer dispersed in water. Thecopolymer dispersion can be prepared with a total solids content of from20% to 70% by weight (e.g., 25% to 65% by weight, 35% to 60% by weight,or 45% to 55% by weight). In some embodiments, the copolymer dispersioncan have a total solids content of 50% or greater by weight. Despite thehigher solids content of the aqueous dispersions, the aqueousdispersions disclosed herein can have a viscosity of 40 cP to 5,000 cP(e.g., from 100-4,000 cP, from 200-3,000 cP, from 300-2,000 cP, from400-1,500 cP, or from 500-1,000 cP) at 20° C. The viscosity can bemeasured using a viscometer with a #2 spindle at 50 rpm at 20° C.

The composition can include one or more surfactants (emulsifiers) suchas nonionic surfactants, anionic surfactants, cationic surfactants,amphoteric surfactants, or a mixture thereof. Suitable nonionicsurfactants include, but are not limited to, polyoxyalkylene alkylethers and polyoxyalkylene alkylphenyl ethers (e.g., diethylene glycolmonoethyl ether, diethylene glycol diethyl ether, polyoxyethylene laurylether, polyoxyethylene stearyl ether, and polyoxyethylene nonylphenylether); oxyethylene-oxypropylene block copolymers; sorbitan fatty acidesters (e.g., sorbitan monolaurate available as SPAN® 20 from MerckSchuchardt OHG, sorbitan monooleate available as SPAN® 80 from MerckSchuchardt OHG, and sorbitan trioleate available as SPAN® 85 from MerckSchuchardt OHG); polyoxyethylene sorbitan fatty acid esters (e.g.,polyoxyethylene sorbitan monolaurate available as TWEEN® 20 and TWEEN®21 from Uniqema, polyoxyethylene sorbitan monopalmitate available asTWEEN® 40 from Uniqema, polyoxyethylene sorbitan monostearate availableas TWEEN® 60, TWEEN® 60K, and TWEEN® 61 from Uniqema, polyoxyethylenesorbitan monooleate available as TWEEN® 80, TWEEN® 80K, and TWEEN® 81from Uniqema, and polyoxyethylene sorbitan trioleate available as TWEEN®85 from Uniqema); polyoxyethylene sorbitol fatty acid esters (e.g.,tetraoleic acid polyoxyethylene sorbitol); glycerin fatty acid esters(e.g., glycerol monooleate); polyoxyethylene glycerin fatty acid esters(e.g., monostearic acid polyoxyethylene glycerin and monooleic acidpolyoxyethylene glycerin); polyoxyethylene fatty acid esters (e.g.,polyethylene glycol monolaurate and polyethylene glycol monooleate);polyoxyethylene alkylamine; and acetylene glycols. In some embodiments,the nonionic surfactant can have a HLB (hydrophilic lipophilic balance)at room temperature such that 8<HLB<15. In some embodiments, the HLB is14 or less. In some embodiments, the nonionic surfactant includes anethylene oxide (EO)_(m) and/or propylene oxide (PO)_(n) adduct of analkyl, alkylbenzene or dialkylbenzene alcohol wherein (m+n)≤14,(m+n)≤12, or (m+n)≤10 (e.g., 6≤(m+n)≤10), such as those available fromBASF under the LUTENSOL™ trademark.

Suitable anionic emulsifiers include fatty acids, alkyl sulfates, alkylether sulfates, alkyl benzene sulfonic acid, alkyl phosphoric acid orsalts thereof, and sucrose esters. Anionic polyelectrolytes such astartrates, borates, oxalates and phosphates, can also be used in thecomposition. Additional suitable anionic surfactants andpolyelectrolytes include but are not limited to M28B and other anionicsurfactants available from MeadWestvaco under the INDULIN® trademark(such as INDULIN® AMS, INDULIN® SA-L, INDULIN® ISE, INDULIN® 201,INDULIN® 202, and INDULIN® 206); anionic surfactants available from AkzoNobel under the REDICOTE® trademark (such as REDICOTE® E-15 andREDICOTE® E-62C); and lignosulfonates such as those available under theMARASPERSE™ trademark (such as MARASPERSE™ CBOS-3 and MARASPERSE™ N22).In some embodiments, the emulsifier includes an anionic fatty acid-basedemulsifier.

Cationic emulsifiers can be classified as cationic rapid setting (CRS),cationic quick setting (CQS), cationic medium setting (CMS), or cationicslow setting (CSS) emulsifiers and these classifications are known inthe art and can be readily measured in an emulsion as set forth in ASTMD977 and D2397. In some embodiments, cationic polyelectrolytes can beprovided in the composition. Suitable cationic emulsifiers andpolyelectrolytes include alkylamine salts, quaternary ammonium salts,cationic surfactants available from Akzo Nobel under the REDICOTE®trademark (such as REDICOTE® 4819, REDICOTE® E-64R, REDICOTE® E-5,REDICOTE® E-9, REDICOTE® E9A, REDICOTE® E-11, REDICOTE® E-16, REDICOTE®E-44, REDICOTE® E-120, REDICOTE® E-250, REDICOTE® E-2199, REDICOTE®E-4868, REDICOTE® C-346, REDICOTE® C.-404, REDICOTE® C.-450, andREDICOTE® C.-471), cationic surfactants available from MeadWestvacounder the INDULIN® and AROSURF® trademarks (such as INDULIN® 814,INDULIN® AMS, INDULIN® DF-30, INDULIN® DF-40, INDULIN® DF-42, INDULIN®DF-60, INDULIN® DF-80, INDULIN® EX, INDULIN® FRC, INDULIN® MQK, INDULIN®MQK-1M, INDULIN® MQ3, INDULIN® QTS, INDULIN® R-20, INDULIN® SBT,INDULIN® W-1, and INDULIN® W-5), ASFIER® N480 available from KaoSpecialties Americas, CYPRO™ 514 available from Cytec Industries,polyethyleneimines such as those available from BASF under the POLYMIN®trademark (such as POLYMIN® SK, POLYMIN® SKA, POLYMIN® 131, POLYMIN®151, POLYMIN® 8209, POLYMIN® P, and POLYMIN® PL), and polyvinylaminessuch as those available from BASF under the CATIOFAST® trademark (suchas CATIOFAST® CS, CATIOFAST® FP, CATIOFAST® GM, and CATIOFAST® PL).Other suitable cationic polyelectrolytes and surfactants include thoselisted in U.S. Pat. Nos. 5,096,495, 5,160,453, and 5,443,632. In someembodiments, the cationic emulsifier includes an amine-based emulsifier.

Suitable amphoteric surfactants include, but are not limited to, betaineacetate, amide betaine, sulfobetaine, imidazolium betaine, and amineoxides. An exemplary amphoteric surfactant is REDICOTE® E-7000surfactant, which is available from Akzo Nobel. Suitable anionicemulsifiers include fatty acids, alkyl sulfates, alkyl ether sulfates,alkyl benzene sulfonic acid, alkyl phosphoric acid or salts thereof, andsucrose esters. Anionic polyelectrolytes such as tartrates, borates,oxalates and phosphates, can also be used in the composition. Additionalsuitable anionic surfactants and polyelectrolytes include but are notlimited to M28B and other anionic surfactants available fromMeadWestvaco under the INDULIN® trademark (such as INDULIN® AMS,INDULIN® SA-L, INDULIN® ISE, INDULIN® 201, INDULIN® 202, and INDULIN®206); anionic surfactants available from Akzo Nobel under the REDICOTE®trademark (such as REDICOTE® E-15 and REDICOTE® E-62C); andlignosulfonates such as those available under the MARASPERSE™ trademark(such as MARASPERSE™ CBOS-3 and MARASPERSE™ N22). In some embodiments,the emulsifier includes an anionic fatty acid-based emulsifier.

The compositions disclosed herein can also be used in any applicationwherein conventional polymers derived from polymerizing a hydrophobicmonomer and/or a gas-phase monomer can be used. The compositionsdisclosed herein can be used in a variety of applications including, butnot limited to, asphalt compositions, paints, coatings, paper bindingand coating compositions (e.g., paper saturation), foams, carpetcompositions, or adhesives. In some embodiments, the copolymerdispersion can be spray dried to produce a powder.

In some embodiments, the copolymer is included in an asphaltcomposition. The asphalt composition can further include one or moreadditives. Suitable additives include inorganic salts, thickeners andfillers. Inorganic salts can be added, for example to improveemulsifiability, in an amount of up to 1 part by weight. Suitableinorganic salts include sodium chloride, potassium chloride, calciumchloride, aluminum chloride and mixtures thereof. Thickeners can beadded in an amount of up to 0.5 parts by weight and can includeassociative thickeners, polyurethanes, alkali swellable latexthickeners, cellulose, cellulose derivatives, modified celluloseproducts, plant and vegetable gums, starches, alkyl amines, polyacrylicresins, carboxyvinyl resins, polyethylene maleic anhydrides,polysaccharides, acrylic copolymers, hydrated lime (such as cationicand/or nonionic lime), or mixtures thereof. Mineral fillers and/orpigments can include calcium carbonate (precipitated or ground), kaolin,clay, talc, diatomaceous earth, mica, barium sulfate, magnesiumcarbonate, vermiculite, graphite, carbon black, alumina, silicas (fumedor precipitated in powders or dispersions), colloidal silica, silicagel, titanium oxides (e.g., titanium dioxide), aluminum hydroxide,aluminum trihydrate, satine white, and magnesium oxide. Fillers such asmineral fillers and carbon black can be included in an amount of up to 5parts by weight or up to 2 parts by weight. For example, the filler canbe provided in an amount of 0.1 part of greater or 0.5 parts or greater.The carbon black can be used to blacken the composition as is desired,for example, in fog seal applications. The mineral filler can beprovided as a fine powder and can be used, for example, to increase theset rate of the asphalt emulsion or to reduce or prevent bleeding of theasphalt. Suitable mineral fillers include hydrated lime, limestone dust,Portland cement, silica, alum, fly ash, and combinations thereof.Mineral filler generally refers to a finely divided mineral productwherein at least 65 percent of which will pass through a No. 200 sieve,and typically has an average size that is less than 0.003 inches.

The composition can also include aggregate. The aggregate can be ofvarying sizes as would be understood by those of skill in the art. Anyaggregate that is traditionally employed in the production of bituminouspaving compositions can be used, including dense-graded aggregate,gap-graded aggregate, open-graded aggregate, reclaimed asphalt pavement,and mixtures thereof. Dense-graded aggregate exhibits the greatestmineral surface area (per unit of aggregate). Open-graded aggregatelargely consist of a single, large-sized (e.g., around 0.375 inch to 1.0inch) stone with very low levels (e.g., less than about two percent ofthe total aggregate) of fines (e.g., material less than 0.25 inch) orfiller (e.g., mineral material less than 0.075 mm). Gap graded aggregatefall between dense-graded and open-graded classes. Reclaimed asphaltpavement (RAP) material generally reflects the gradation of the pavementfrom which the reclaimed material was obtained. If the original pavementwas a dense-graded mix, the RAP will also be dense graded, although thefiller content is generally observed to be lower than the design limitsof the origin aggregate specifications. The aggregate can be applied inan amount of from 100 parts by weight to 2000 parts by weight.

Compositions that include aggregate can also include air voids in someembodiments. The air voids can be present in an amount of from 2% to 30%by volume (e.g., greater than 2% to 10% by volume).

An asphalt composition can be prepared by mixing asphalt, any aromaticrecycling agents or non-asphaltic rosin materials, copolymer (forexample, in the form of a latex dispersion), emulsifier, acid or base,water and any additives. The particular components can be mixed togetherby means known in the art. In some embodiments, the copolymer ispre-mixed with an anionic emulsifier or a cationic emulsifier to producea charged copolymer before mixing the asphalt and the acid or base withthe emulsifier and the copolymer. If aggregate is blended into theasphalt composition, it can be added, for example, after the othercomponents are blended. In some embodiments, the asphalt composition isprepared at an elevated temperature, for example, from 160° C. to 200°C. (hot mix asphalt), from 120° C. to 140° C. (warm mix asphalt), or attemperatures below 120° C. (e.g., from 50° C. to 100° C. or from 60° C.to 80° C.). In some embodiments, the asphalt composition can be preparedat ambient temperature.

The asphalt composition can be applied for use in a pavement or pavedsurface. A pavement surface or a paved surface is a hard surface thatcan bear pedestrian or vehicular travel can include surfaces such asmotorways/roads, parking lots, bridges/overpasses, runways, driveways,vehicular paths, running paths, walkways, and the like. The asphaltcomposition can be applied directly to an existing paved surface or canbe applied to an unpaved surface. In some embodiments, the compositionis applied to an existing paved layer as a tie layer, and a new layercomprising asphalt such as a hot mix layer is applied to the tie layer.The asphalt composition can be applied to a surface “cold”, i.e., at atemperature below 40° C., or can be applied to at an elevatedtemperature, for example, from 50° C. to 120° C., from 55° C. to 100°C., or from 60° C. to 80° C.

In some embodiments, aggregate is blended into the asphalt compositionbefore application to a surface. In some embodiments, aggregate isapplied to the composition after it is applied to a surface. In someembodiments, sand can be applied to the composition after it is appliedto a surface, for example, if the composition is to be used as a tackcoat, to reduce the tackiness of the surface. The composition andoptionally the aggregate can be compacted after application to thesurface as would be understood by those of skill in the art.

In some embodiments, the composition is used as a tack coat or coating.The tack coat is a very light spray application of diluted asphaltemulsion that is used to promote a bond between an existing surface andthe new asphalt application. The tack coat acts to provide a degree ofadhesion or bonding between asphalt layers, and in some instances, mayfuse the layers together. The tack coat also acts to reduce slippage andsliding of the layers relative to other layers in the pavement structureduring use or due to wear and weathering of the pavement structure. Asdescribed above, the composition can be applied to an existing pavedlayer (such as a hot mix layer) as a tie layer as a tack coat, and a newlayer comprising asphalt such as a hot mix layer can be applied to thetack coat. As would be understood by those skilled in the art, the tackcoat typically does not include aggregate, although sand may be appliedto the tack coat after application as mentioned above. The compositiondescribed herein has unexpectedly been found to be a low-tracking or“trackless” coating such that, after the tack coating is cured, pavingvehicles or other traffic may be permitted to pass over the coating suchthat the vehicle tires or treads stick to the coating a limited amount(low track) or not at all (trackless). The composition described hereinhas unexpectedly been found to be low-tracking or “trackless,” forexample, at higher pavement temperatures (50° C.-60° C.) and/or with lowor medium pen asphalts having a pen value of greater than 40 dmm. Thetack coat is tacky and capable of bonding together layers of a pavementstructure at ambient conditions for pavement construction or at elevatedtemperatures, e.g., up to 140° C. as discussed above. In fact, the tackcoat provides a sufficiently flexible asphalt at low temperatures withsufficient bond strength to bond adjacent asphalt layers. The tack coatcures quickly such that the pavement layer may be applied to thecoating, hours to days after the emulsion is applied to the substrate.The applied composition can cure in 15 minutes to 45 minutes, and maycure as rapidly as 5 minutes to 15 minutes after the composition isapplied to the exposed surface. The cure rate will depend on theapplication rate, the dilution ratios used, the base course conditions,the weather, and other similar considerations. If the prepared pavementsurface or base course contains excess moisture, the curing time of theemulsion may be increased.

In some embodiments, the composition can also be used as a fog seal. Afog seal is a surface treatment that applies a light application of thecomposition to an existing paved surface such as a parking lot toprovide an enriched pavement surface that looks fresh and black. In someembodiments, the fog seal would include a filler such as carbon black toblacken the composition. As would be understood by those skilled in theart, the fog seal might not include aggregate. The fog sealcompositions, like the bond coat compositions, have also been shown tobe to be low-tracking or “trackless” coatings.

In some embodiments for the tack coat and fog seal, the asphalt can bepresent in an amount of from 58 to 62 parts by weight, the copolymer canbe present in an amount of from 2 to 6 parts by weight, the emulsifiercan be present in an amount of from 0.75 to 3 parts by weight, the acidor base can be present in an amount of from 0.75 to 3 parts by weight,any optional additives be provided in an amount of up to 5 parts byweight, and water can be present in an amount of from 30 to 40 parts byweight. In some embodiments, the composition can be further diluted withwater. The composition can be applied at a rate of 0.05-0.10gallons/yd².

In some embodiments, the composition can be used as a chip sealcomposition. Chip seals are the most common surface treatment forlow-volume roads. The chip seal composition can be applied to a surfacefollowed by the application of aggregate. In some embodiments for thechip seal, the asphalt can be present in an amount of from 64 to 67parts by weight, the copolymer can be present in an amount of from 1.5to 3.5 parts by weight, the emulsifier can be present in an amount offrom 0.15 to 0.35 parts by weight, the acid or base can be present in anamount of from 0.15 to 0.35 parts by weight, any optional additives beprovided in an amount of up to 5 parts by weight, and water can bepresent in an amount of from 30 to 40 parts by weight. The aggregate canbe provided in an amount of from 200 to 1000 parts by weight.

In some embodiments, the composition can be used as a microsurfacingapplication. Microsurfacing is designed for quick traffic return withthe capacity of handling high traffic volume roadways. For themicrosurfacing composition, aggregate can be mixed in with the asphalt,copolymer, emulsifier and acid or base before application to a surface.In some embodiments for the microsurfacing, the asphalt can be presentin an amount of from 60 to 62 parts by weight, the copolymer can bepresent in an amount of from 3 to 4.5 parts by weight, the emulsifiercan be present in an amount of from 0.5 to 2.5 parts by weight, the acidor base can be present in an amount of from 0.5 to 2.5 parts by weight,any optional additives be provided in an amount of up to 5 parts byweight (e.g., 0.25 to 2 parts by weight of one or more inorganic saltsor up to 5 parts by weight of a mineral filler), and water can bepresent in an amount of from 30 to 40 parts by weight. The aggregate canbe provided in an amount of from 500 to 2000 parts by weight.

The resulting paved surface layer using the composition, once dried,includes the components provided in the composition with the exceptionof water. Thus, the paved surface layer can include asphalt in an amountof from 40 to 70 parts by weight, a copolymer in an amount of fromgreater than 0 to 10 parts by weight, an emulsifier in an amount of from0.1 to 4 parts by weight, and an acid or base in an amount of from 0.1to 4 parts by weight. In the case of a tack coat, the paved surface caninclude a first layer comprising asphalt; a tie layer provided on thefirst layer, comprising asphalt in an amount of from 40 to 70 parts byweight, the copolymer in an amount of from greater than 0 to 10 parts byweight, an emulsifier in an amount of from 0.1 to 4 parts by weight, andan acid or base in an amount of from 0.1 to 4 parts by weight; and asecond layer comprising asphalt provided on the tie layer.

Although parts by weight are used for the compositions described herein,percentages by weight could be used interchangeability with the parts byweight, for example, where the composition includes the asphalt, thecopolymer, the emulsifier, the acid or base, the water, and anyadditives excluding aggregate. For example, the composition can bedescribed to include (a) asphalt in an amount of from 40 to 70 percentby weight; (b) a copolymer in an amount of from greater than 0 to 10percent by weight; (c) an emulsifier in an amount of from 0.1 to 4percent by weight; (d) an acid or a base in an amount of from 0.1 to 4percent by weight; and (e) water in an amount of from 25 to 60 percentby weight.

In some embodiments, the compositions disclosed herein can be used inpaints, coatings, paper coating or binding compositions, carpetcompositions (e.g., carpet backing), foams, or adhesives. In someembodiments, one or more thickeners (rheology modifiers) can be added toincrease the viscosity of the composition. Suitable thickeners caninclude, but are not limited to, acrylic copolymer dispersions soldunder the STEROCOLL and LATEKOLL trademarks from BASF Corporation,Florham Park, N.J., hydroxyethyl cellulose, guar gum, jaguar,carrageenan, xanthan, acetan, konjac, mannan, xyloglucan, urethanes andmixtures thereof. The thickeners can be added to the compositionformulation as an aqueous dispersion or emulsion, or as a solid powder.

The composition described herein can include, for instance, additivessuch as dispersants, initiators, stabilizers, chain transfer agents,buffering agents, salts, preservatives, fire retardants, wetting agents,protective colloids, biocides, corrosion inhibitors, crosslinkingpromoters, and lubricants. Exemplary dispersants can include sodiumpolyacrylates in aqueous solution such as those sold under the DARVANtrademark by R.T. Vanderbilt Co., Norwalk, Conn.

Paint and coating compositions can, for instance, include one or morepigments or dyes. Exemplary composition pigments include titaniumdioxide composition pigments, MIRAGLOSS 91 (a kaolin clay compositionpigment commercially available from BASF Corporation), LOPAQUE M (akaolin clay composition pigment commercially available from ThieleKaolin Company), and HYDROCARB 90 (a calcium carbonate compositionpigment commercially available from Omya Paper). In some embodiments,the composition can include one or more dyes or colored pigments.Exemplary dyes can include basic dyes, acid dyes, anionic direct dyes,and cationic direct dyes. Exemplary colored pigments include organicpigments and inorganic pigments in the form of anionic pigmentdispersions and cationic pigment dispersions.

The methods disclosed herein can be used for the production ofhigh-butadiene content styrene-butadiene or carboxylatedstyrene-butadiene latexes at lower polymerization pressures, lowertemperatures, lower reaction times, or a combination thereof, comparedto the pressures, temperatures, and reaction times of the samepolymerization without solid grade oligomer. Lower polymerizationpressures or lower temperatures can lead to increased plant safety.Lower reaction times can lead to increased plant efficiency andproductivity. Additionally, the methods disclosed herein can lead tocost savings in polymer manufacture including, but not limited to,savings associated reduced energy use and savings associated with adecreased need for specialized equipment (e.g., high pressure reactors).Solid grade oligomer modified polymers, when used to modify, forinstance, hot asphalt, can result in lower viscosity and improvedperformance.

By way of non-limiting illustration, examples of certain embodiments ofthe present disclosure are given below.

EXAMPLES

In Example 1, a copolymer derived from 50 parts by weight styrene, 50parts by weight butadiene, and 20 parts by solid grade oligomer (SGOB-98) was produced. A styrene feed, a butadiene feed, an initiator feedcomprising an aqueous solution of sodium persulfate initiator (0.6 partsby weight of the total monomers), were added over 6 hours to apre-heated reactor (70° C.) containing water, the solid grade oligomer,sodium hydroxide (0.14 parts by weight of the total monomers), apolystyrene seed latex (1.66 parts by weight of the total monomers), andTRILON BX (0.03 parts by weight of the total monomers), anethylenediaminetetraacetic acid commercially available from BASFCorporation (Florham Park, N.J.). The stabilization of the latexparticles during polymerization was accomplished by feeding an aqueoussolution of potassium oleate surfactant (3.6 parts by weight of thetotal monomers) over the course of the polymerization. The temperaturewas maintained at 70° C. throughout the polymerization reaction.Following the polymerization process, the latex dispersion was strippedof the residual monomers to provide an aqueous dispersion with residualstyrene levels of less than 400 ppm.

Examples 2-7 and Comparative Example 1 were conducted in the same manneras Example 1 except with the differences shown in Table 1. Table 1 alsoillustrates the pH, viscosity, volume average particle size, numberaverage particle size, and percent solids (% TS) for these compositions.

TABLE 1 SGO MODIFIED STYRENE-BUTADIENE LATEXES—PHYSICAL PROPERTIES SGOParticle Particle LEVEL, Visc Size Size pts on % SGO (cPs) Volume NumberSGO total in the #2 @ (nm) (nm) Example Used monomer S BU particle pH 50rpm avg avg % TS 1 B-98 20 50 50 16.7 8 165.0 154.7 49.7 (48 nm, 45.60(55 nm, 145 nm) 148 nm) 2 B-98 25 50 50 20 7.8 50.0 57.1 44.3 45.70(wide) (wide) 3 B-98 25 50 50 20 7.8 73.0 54.4 (40 nm, 37.6 46.30 89 nm)(wide) 4 B-98 30 50 50 23.1 8.4 45.0 40.70 5 E-26 20 50 50 16.7 7.81982.0 386 96 39.70 6 B-98 20 40 60 16.7 8.1 56 67 52 42.6 7 B-98 20 3070 16.7 8.45 54 41.2 Comp. Ex. 1 None 0 50 50 0 9.4 25 120 100 41.32

FIGS. 1 and 2 illustrate the reaction temperatures and pressures overrun time for the dispersions of Comparative Example 1 and Example 1,respectively, during emulsion polymerization at 70° C. As shown in thesefigures, the emulsion polymerization process conducted using the solidgrade oligomer was conducted at a lower pressure over the same run timewhile maintaining the same temperature.

FIGS. 3 and 4 illustrate the alternative copolymer compositions ofExamples 6 and 7 that include different amounts of styrene and butadienethan provided in Example 1. These figures also illustrate an emulsionpolymerization processes conducted at lower pressures.

FIG. 5 illustrates an alternative copolymer composition of Example 5that includes SGO E-26, a different solid grade oligomer than providedin Example 1. FIG. 5 also illustrates an emulsion polymerization processconducted at lower pressure. FIG. 6 illustrates the alternativecopolymer composition of Example 5 that includes SGO E-08, a differentsolid grade oligomer than provided in Example 1. The resultant latexwhen using SGO E-08 was of compromised stability and very thick, with aviscosity in excess of 15,000 cp. These figures illustrate that althoughthe emulsion polymerization processes were conducted at lower pressuresinitially, the polymerization pressure increased in the final stage to alevel similar to that of the process that uses no solid grade oligomer(SGO).

FIG. 7 illustrates a comparison of temperature to complex modulus forcopolymers comprising 50 parts by weight styrene, 50 parts by weightbutadiene, and various amounts of solid grade oligomer (SGO), and forcommercial styrene-butadiene latices used in asphalt compositions(Comparative Examples 2 and 3). FIG. 8 illustrates a comparison oftemperature to complex modulus for copolymers comprising 20 parts ofsolid grade oligomer (SGO) and various amounts of styrene and butadiene,and for Comparative Examples 2 and 3. As demonstrated by these figures,the copolymers produced using the SGOs have greater elasticity at hightemperatures (i.e., greater than 70° C.), which is desirable in manyapplications including asphalt applications. In addition, at low andintermediate temperatures, i.e., in the 0-70° C. range, the copolymersdescribed herein can be designed by adjusting the SGO level and/or thestyrene/butadiene ratio to produce differentiated complex modulusprofiles depending on the desired application.

FIG. 9 illustrates the temperature and pressure over run time for thepolymerization of a copolymer comprising 50 parts by weight styrene, 50parts by weight butadiene, and 20 parts by weight solid grade oligomer(SGO) and depicting a decrease in polymerization time, and resulting ina solids content of 53%. FIG. 10 illustrates a similar sample with asolids content of 50%. FIGS. 9 and 10 represent a 2.25 hr feed timepolymerization process compared to 6 hrs for the same polymerization(such as the one conducted for Comparative Example 1) in the absence ofthe solid grade oligomer (SGO).

Latex Polymer-Modified Asphalt Sample Preparation

Asphalt cement was preheated to 160° C.+/−3° C. for at least two hoursand then 650 grams of the heated asphalt cement was poured into ametallic can. The asphalt-containing can was heated to 170° C.+/−3° C.using a heating mantle. A blade was inserted at an angle atapproximately 20° in the middle of the can to provide optimum mixing.The latex prepared according to the method described above was addedslowly to the hot asphalt with mixing at 300-325 rpm. Unless otherwisespecified, the amount of latex polymer solids added to the asphalt was 3wt % based on the total solids content of the latex polymer and asphalt.After each addition, time was allowed for most of the bubbling to ceaseand then the mixer speed was increased to approximately 400-700 rpm toblend the resulting mixture. After latex addition, the mixing wascontinued for two additional hours to achieve an equilibrated asphaltpolymer mixture. Samples of the polymer modified asphalts were taken forviscosity measurement or poured into molds for any desired testing.

SHRP Binder Testing of Latex Polymer-Modified Asphalt

The Strategic Highway Research Program (SHRP) evaluation of latexpolymer modified asphalts was carried out according to the ASTM D7175 orAASHTO T315 procedure on the original latex polymer modified asphalt, onthe latex polymer modified asphalt following Rolling Thin-Film Oven(RTFO) exposure, and also on the RTFO conditioned latex polymer modifiedasphalt that was conditioned in the Pressure Aging Vessel (PAV). TheDynamic Shear Rheometer (DSR) tests measure the dynamic shear modulusand stiffness of the latex polymer modified asphalt. In addition,Bending Beam Rheometer (BBR) testing was carried out according to ASTMD6678 or AASHTO T313 to measure the low temperature stiffnesscharacteristics of the latex polymer modified asphalt binders. Testingof the original (unaged or fresh) latex polymer modified asphalt and ofthe latex polymer modified asphalt after RTFO exposure provided the HighTemperature in the Performance Grade (PG) scale. Testing of the latexpolymer modified asphalt after RTFO and PAV exposure provided thestiffness at intermediate temperatures related to fatigue resistance andBBR testing after RTFO and PAV exposure provided the Low Temperature inthe PG scale.

Viscosity of Latex Polymer-Modified Asphalt

The viscosities of the latex polymer modified asphalts preparedaccording to the methods described above were measured according to ASTMD4402 or AASHTO T316 (American Association of State Highway andTransportation Officials).

FIG. 11 depicts the impact of certain styrene butadiene copolymers,including copolymers as described in this disclosure (Examples 1, 2, 4,6 and 7), on asphalt viscosity. Examples 8-12 are based on Examples 1,2, 4, 6 and 7, respectively, and further include 2.1% by weight of asulfur crosslinking agent, based on the weight of asphalt. In additionto Comparative Examples 1 and 3, a control was provided including NUSTAR64-22 asphalt as well as a comparative example (Comparative Example 4, acommercial styrene-butadiene latex used in asphalt composition andsimilar to Comparative Example 3, but with a higher amount of a chaintransfer agent). As depicted in this figure, the copolymers includingthe SGO had improved viscosity over the comparative examples notincluding a SGO. In addition, although not illustrated, the High SHRPTemperature increased by one Performance Grade (PG) when the copolymersbased on the SGO were added at a 3 wt % dry polymer-to-asphalt level toNUSTAR 64-22 asphalt, either alone or in combination with 2.1 wt % of asulfur-based crosslinking agent, based on the weight of asphalt. The LowSHRP Temperature of the NUSTAR 64-22 asphalt was extended to −28° C. forsome of the copolymers based on the SGO at a 3 wt % drypolymer-to-asphalt level.

The compositions and methods of the appended claims are not limited inscope by the specific compositions and methods described herein, whichare intended as illustrations of a few aspects of the claims and anycompositions and methods that are functionally equivalent are intendedto fall within the scope of the claims. Various modifications of thecompositions and methods in addition to those shown and described hereinare intended to fall within the scope of the appended claims. Further,while only certain representative compositions and method stepsdisclosed herein are specifically described, other combinations of thecompositions and method steps also are intended to fall within the scopeof the appended claims, even if not specifically recited. Thus, acombination of steps, elements, components, or constituents may beexplicitly mentioned herein or less, however, other combinations ofsteps, elements, components, and constituents are included, even thoughnot explicitly stated. The term “comprising” and variations thereof asused herein is used synonymously with the term “including” andvariations thereof and are open, non-limiting terms. Although the terms“comprising” and “including” have been used herein to describe variousembodiments, the terms “consisting essentially of” and “consisting of”can be used in place of “comprising” and “including” to provide for morespecific embodiments of the invention and are also disclosed. Other thanin the examples, or where otherwise noted, all numbers expressingquantities of ingredients, reaction conditions, and so forth used in thespecification and claims are to be understood at the very least, and notas an attempt to limit the application of the doctrine of equivalents tothe scope of the claims, to be construed in light of the number ofsignificant digits and ordinary rounding approaches.

What is claimed is:
 1. A composition comprising: a copolymer derivedfrom polymerizing hydrophobic monomers comprising from 25%-59% by weightstyrene and from 25%-59% by weight butadiene in an aqueous medium and inthe presence of from 8%-25% by weight of an oligomer, wherein thepercents by weight are based on the total monomer weight of thecopolymer, wherein the hydrophobic monomers have a solubility in wateras measured at 20° C. of 1 g/100 g water or less, wherein the oligomeris derived from a vinyl aromatic monomer, and wherein the copolymer isderived from 65% by weight or greater of the hydrophobic monomers, basedon the total monomer weight of the copolymer.
 2. The compositionaccording to claim 1, wherein the copolymer is further derived from ahydrophilic monomer, wherein the hydrophilic monomer includes acarboxylic acid monomer.
 3. The composition according to claim 1,wherein the hydrophobic monomers further include a carboxylic acid-basedhydrophobic monomer.
 4. The composition according to claim 3, whereinthe hydrophobic monomers include a (meth)acrylic acid-based hydrophobicmonomer.
 5. The composition according to claim 1, wherein copolymer isderived from polymerizing from 42%-59% by weight butadiene, wherein thepercents by weight are based on the total monomer weight of thecopolymer.
 6. The composition according to claim 1, wherein the vinylaromatic monomer is selected from styrene, α-methyl styrene, or acombination thereof.
 7. The composition according to claim 6, whereinthe oligomer is further derived from a carboxylic acid monomer, or asalt or ester thereof.
 8. The composition according to claim 7, whereinthe carboxylic acid monomer includes acrylic acid.
 9. The compositionaccording to claim 1, wherein the oligomer is an amine salt of amodified acrylic copolymer, an ammonium salt of a modified acryliccopolymer, or a combination thereof.
 10. The composition according toclaim 1, wherein the composition is an aqueous dispersion comprising thecopolymer and the aqueous dispersion has a solids content of at least50% by weight.
 11. An asphalt composition comprising the compositionaccording to claim
 1. 12. A method of preparing a copolymer according toclaim 1, comprising: polymerizing hydrophobic monomers comprising from25%-59% by weight styrene and from 25%-59% by weight butadiene in thepresence of from 8%-25% by weight of an oligomer in an aqueous medium,wherein the percents by weight are based on the total monomer weight ofthe copolymer, wherein the hydrophobic monomers have a solubility inwater as measured at 20° C. of 1 g/100 g water or less, wherein theoligomer is derived from a vinyl aromatic monomer, and wherein thecopolymer is derived from 65% by weight or greater of the hydrophobicmonomers, based on the total monomer weight of the copolymer.
 13. Themethod according to claim 12, wherein the polymerizing step is anemulsion polymerization step.
 14. The method according to claim 12,further comprising crosslinking the copolymer using ionic crosslinking.